An agricultural crop spraying machine is designed to effectively distribute an agro-chemical spray over the largest area of crop in the least amount of time. The conventional design for such a machine is a wheeled base unit, be it trailed or self-propelled, which carries a tank, pump, and controls. The conventional design supplies the agro-chemical to the distribution booms extending from either side of the wheeled base unit, perpendicular to the direction of travel.
Nozzle holders (or nozzle bodies) are placed at regular intervals along the spray boom. The primary role of the nozzle holders is to provide a sealed connection between the pipe work of the boom supply and the spray nozzles distributing the agro-chemical. The nozzle holders also position the spray nozzles at the correct angle with respect to the direction of travel.
Some conventional nozzle holders include a check valve to ensure that the spray nozzles do not operate until sufficient line pressure is present to generate an acceptable spray. A diaphragm check valve for conventional nozzle holders has almost become a standard size, which allows accessory items, such as air operated shut-off valves, to be retrofitted.
Some conventional nozzle holders can receive different types of spray nozzles, so the operator can select the most appropriate combination of spray nozzles for a given application without the need for component changes.
In recent years, there has been a growing trend toward machines with a higher flow rate capacity to allow spraying needs to be increased while maintaining application rates per unit area. Although machine components can be increased in size to achieve increased flow capacities, there is particular emphasis directed at keeping the size and/or weight of the boom components to a minimum. This is necessary to minimize the potential for grounding and loading on the booms.